Even with life-saving vaccines and antibiotics, tuberculosis (TB) remains one of the world’s most deadly infectious diseases. Now, an international clinical trial has found three sew safe and effective drug regimens to treat antibiotic-resistant strains of TB. The results are detailed in a study published January 30 in the New England Journal of Medicine.
Why is tuberculosis still dangerous?
TB is a bacterial infection that primarily affects the lungs. It spreads through air droplets released when talking or coughing. It is very infectious and can remain in the air for several hours, depending on the environment. However, TB only spreads when a person is symptomatic.
It can take on two forms once the bacterium infects a person. Active TB is when a patient has a long-standing cough, in addition to other symptoms including bloody phlegm, fever, and night sweats. In latent TB, the bacterium hibernates a person’s lungs or somewhere else in the body. Latent TB is not contagious and doesn’t cause symptoms.
According to the Cleveland Clinic, roughly 10 million people became ill with TB and about 1.5 million people died from the disease globally in 2020. There were roughly 7,860 tuberculosis cases reported in the United States in 2021.
Currently, an outbreak centered in the Kansas City, Kansas area has killed two people since it began last January. The Kansas Department of Health and Environment reported that 67 people are being treated for active TB and 79 have latent TB.
“We would expect to see a handful of cases every year,” Dr. Dana Hawkinson, an infectious disease doctor at the University of Kansas Health System, told the Associated Press. However, Hawkinson said that the high case counts in this current outbreak were a “stark warning.”
In October, the World Health Organization’s (WHO) Global Tuberculosis Report 2024 found that reported cases increased from 7.5 million in 2022 to 8.2 million last year. Disruptions to vaccination schedules due to the COVID-19 pandemic and drug-resistant strains were cited as potential reasons for the increases.
Since it is a bacterial illness and not a virus like influenza, antibiotic resistance is a growing concern. Some TB strains are already resistant to rifampin, the most effective of the first-line antibiotics used to treat the disease. Rifampin and some other approved treatment regimens must be administered for years, require daily injections, and use some highly toxic medications that can come with severe side-effects.
The endTB trials
This new research is part of the endTB trial, a collaboration among Harvard Medical School, Partners In Health, Médecins Sans Frontières, and Interactive Research and Development.
The endTB trial is one of four recent randomized controlled trials testing new, shorter, and less toxic treatment regimens for drug-resistant TB. The trials are using two fairly new drugs—bedaquiline and delamanid. The medicines were first brought to the market in 2012 and 2013 and were the first new medications for TB in almost 50 years.
The trial launched in 2017 with 754 patients from India, Georgia, Kazakhstan, Lesotho, Pakistan, Peru, and South Africa. The goal was to improve treatment for patients with tuberculosis resistant to rifampin which sickens about 410,000 people each year. Only 40 percent are diagnosed and treated, 65 percent of them successfully, according to the World Health Organization (WHO).
[ Related: How infectious diseases killed Victorian children at alarming rates. ]
In the trial, endTB tested five new, all-oral regimens using bedaquiline and delamanid in combination with other drugs. The regimens were taken over nine months. A third drug–pretomanid–received emergency authorization from the FDA in 2019. However, it is not included in these trials.
Three out of the five new regimens were considered successful for between 85 and 90 percent of patients with this treatment-resistent strain of TB. The control group was treated with longer treatments and was successful in 81 percent of cases.
According to the team, the trial regimens were considered effective if they performed at least as well as the control group. The control group still received a well-performing standard of care in accordance with WHO recommendations.
A step towards more accessible care
Two of the three new endTB regimens and another WHO-recommended regimen cost under $500, to meet a target set over 10 years ago. All of these innovations together could mean that shorter, all-oral regimens are available to more people than ever.
“This Harvard-led partnership among NGOs, ministries of health, and other academic partners identified three new regimens that will make lifesaving care dramatically more accessible,” Carole Mitnick, trial co-principal investigator and Harvard Medical School epidemiologist, said in a statement. “We also resolved a critical question left open by pharmaceutical industry trials that brought bedaquiline and delamanid to market: How can these new drugs be used to shorten and simplify treatment while retaining efficacy?”
According to Mitnick, poor treatment options and low-quality evidence previously have made it difficult to prevent some tuberculosis deaths. These new regimens take advantage of already approved drugs to expand and shorten treatment, minimize side effects, and treat patients using pills instead of daily injections. The endTB trials have since concluded.
More deals, reviews, and buying guides
